Perylene Bisimide Cyclophanes: Structure-Property Relationships upon Variation of the Cavity Size

Jessica Rühe, David Bialas, Peter Spenst, Ana Maria Krause, Frank Würthner

Research output: Contribution to journalArticlepeer-review

10 Scopus citations

Abstract

Five cyclophanes composed of two perylene bisimide (PBI) dyes and various CH2-arylene-CH2linker units were synthesized. PM6-D3H4 geometry-optimized structures and a single crystal for one of these cyclophanes reveal well-defined distances between the two coplanar PBI units in these cyclophanes, spanning the range from 5.0 to 12.5 Å. UV/vis absorption spectra reveal a redistribution of oscillator strength of the vibronic bands due to a H-type exciton coupling even for the cyclophane with the largest interchromophoric distance. A quantitative evaluation according to the Kasha-Spano theory affords exciton coupling strengths ranging from 64 cm-1for the largest cyclophane up to 333 cm-1for the smallest one and a surprisingly good fit to the cubic interchromophoric distance in the framework of the point-dipole approximation. Interchromophoric interaction is also noticed in fluorescence lifetimes that are significantly increased for all five cyclophanes as expected for H-coupled chromophores due to a decrease of the radiative rate. For the three largest cyclophanes with interchromophoric distances of >9 Å, fluorescence quantum yields remain high in chloroform (>88%), whilst for the smaller ones with interchromophoric distances <6 Å, additional nonradiative pathways lead to a pronounced fluorescence quenching.

Original languageEnglish (US)
Pages (from-to)149-158
Number of pages10
JournalOrganic Materials
Volume2
Issue number2
DOIs
StatePublished - Apr 28 2020

All Science Journal Classification (ASJC) codes

  • Organic Chemistry

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